There are many seasonal wildflowers on the Overlook and Montini trails. See the checklist of seasonal wildflowers for all of their names and when they tend to be flowering, or check out the photos and descriptions of some of favorites below.
Perhaps the flagship flower on the trails is the California Poppy, Eschscholzia californica. It is seen from early spring in profusion to late summer in much reduced numbers. If you are hiking anytime from February to September you are likely to see it, although it is truly spectacular in the Spring. The don’t call this the Golden State for nothing.
The Yellow Mariposa Lily, Calochortus luteus. It frequents the coastal ranges of California, including the hills around Sonoma. You can sometimes find small insects inspecting the interior of the flower.
There are many varieties of Lupine in California. Here is a picture of one variety you will see on the trails. Lupine blooms in early Spring, but is normally gone by mid-Summer.
Dandelions can be seen along the trail as well.
The Toyon bush, or Heteromeles arbutifolia, is prevalent in chapparal and mixed evergreen forest habitats, and is most showy in winter, when the bright red berries are often glistening in the rain. Because of their color and the time when they appear, the Toyon is also known as “Christmas berry” and “Christmas holly.” It is even claimed that the profusion of this plant in the hills above Los Angeles led to the name “Hollywood.”
Early spring is when you will see the Blue Dicks (Dichelostemma capitatum) in profusion. These clustered flowers appear on the end of long, thin stems and are pretty from both the front and the back. They often attract butterflies and other insects.

Mimulus aurantiacus or Sticky Monkey Flower